Why a full renovation is a different animal from an extension
A full house renovation is the most complex residential construction project a domestic contractor can take on. It is not 'a big extension' — it is dozens of interlocking trades and decisions sequenced over 16–36 weeks, in a property where every floor, ceiling, wall, service and finish is being touched. It requires structural design across multiple rooms, full coordination of MEP (mechanical, electrical, plumbing) services from scratch, careful sequencing to avoid out-of-order trades, project-level cost modelling rather than line-item quotes, and a project manager who is on the ground daily. Most general contractors who quote enthusiastically for extensions struggle with full renovations because the variables explode: 50+ decisions on flooring, 40+ on lighting, 100+ on joinery details. We have a dedicated renovation team that has delivered 35+ whole-house projects in the past three years and has standard templates for project programme, cost model, decision schedule and finish specification.
Structural reconfiguration: opening up Victorian and Edwardian layouts
Most London renovation projects involve significant structural change to the original layout. Victorian terraces were built with small rooms, long hallways and dark middle bedrooms — incompatible with modern open-plan living. Typical interventions: remove the wall between front parlour and dining room to create a knock-through living space (one steel beam, two pad-stones, careful detailing of the ceiling junction); remove the wall between kitchen and dining room (another beam, often combined with a side return or rear extension); knock through the upstairs middle bedroom into a master suite with ensuite (usually no steel needed — non-loadbearing walls); open the loft via removal of the original loft hatch and installation of a fixed staircase (structural floor calculations needed). Each intervention is signed off by our in-house structural engineer, calculations submitted to building control, party-wall agreements served where the existing structure adjoins a neighbour.
Full rewire and replumb: what every London Victorian needs
Any pre-1970 London property has services at end-of-life: original wiring is rubber-insulated and brittle, often without earth on lighting circuits; original plumbing is lead, iron or early copper with internal corrosion narrowing flows to a trickle; original heating is single-zone, no thermostat, no boiler interlock. A full renovation is the moment to redo all of this — once walls and floors are open, the cost of new services is incremental, whereas retrofitting later means re-opening finished walls at five times the cost. Standard spec: full rewire to current 18th Edition (BS 7671) with AFDD on all final circuits, RCBO at the consumer unit, smart thermostats per heating zone (typically 5–7 zones per house), CAT6 to every room, full LED lighting design with dimming, USB-C outlets where useful. Plumbing: full replumb in copper or PEX-Al-PEX, unvented hot water cylinder or combi for smaller properties, megaflow + heat pump for high-spec. Drainage: usually replaced from inside the property to the boundary.
MVHR, insulation and the airtightness reality of older London homes
Victorian terraces leak. The original construction — solid 9-inch brick walls, single-glazed sash windows, suspended timber ground floors with no insulation, no underfloor insulation, no airtightness layer — has an air permeability of 15–25 m³/h.m² at 50 Pa, against a new-build target of <5. Heating bills are 3–4x what they should be, comfort is poor, mould is common at thermal bridges. A serious renovation fixes this: internal wall insulation (50–100mm PIR or wood-fibre) where external aesthetics must be preserved; underfloor insulation (typically 100mm between joists with sheep wool or PIR); roof insulation to current standards (300mm in cold roofs); upgraded glazing (slim-profile double or vacuum where heritage glazing is required); airtightness membrane and tape detailing throughout; mechanical ventilation with heat recovery (MVHR) to manage moisture and IAQ without losing heat. Result: typical retrofit improves SAP rating from 30s to 60s, cuts heating bills 40–60%, eliminates condensation issues. We deliver this as standard on full renovations.
Joinery and finishes: the difference between a £2,000/m² and a £5,000/m² renovation
Above the structural and services spec, finish is where renovation cost diverges. £2,000/m² delivers a tidy, magazine-friendly result: white-painted walls, mid-range engineered oak flooring, off-the-shelf doors and architrave, standard ceramic tiling in bathrooms, Howdens-or-equivalent kitchen with quartz worktops. £5,000/m² delivers a high-spec finish: hand-built joinery throughout (built-in wardrobes in every bedroom, panelled hallways, dressing rooms), specified flooring (wide-board engineered oak in herringbone, large-format porcelain, polished concrete), architectural lighting design with track, recessed and feature pendants, marble or large-format porcelain bathrooms with concealed cisterns and walk-in showers, bespoke kitchen in painted hardwood with stone worktops and integrated premium appliances. The structural and services costs are similar; the difference is finish hours, material quality and joinery content. We model the project at both ends of the range so you can decide where to invest.
Sequencing and programme: 24 weeks isn't four extensions back-to-back
A 24-week full renovation isn't four 6-week extensions in series. The work is layered: structure first (4–6 weeks of strip-out, steels, foundations, brick repair), then services first fix (3–4 weeks — electrics, plumbing, heating pipework, MVHR ductwork, all in walls and floors), then insulation and dry lining (3 weeks), then second fix services (2 weeks), then plastering and decoration (3 weeks), then joinery and flooring (3 weeks), then snagging and handover (1–2 weeks). The critical path runs through structural sign-off (which gates first fix) and plaster drying (which gates second fix and decoration). Our project programme is published as a Gantt chart at contract sign and updated weekly. Variations to scope are managed through written variation orders with cost and programme impact — never verbal. The result is a programme that lands within 1–2 weeks of target on 85%+ of projects.
Living arrangements: most clients move out, here's why and what to budget
Unlike single-room extensions where clients stay in residence, a full house renovation is genuinely unliveable for most or all of the project. The whole property is a building site: floors are up, services are off, dust is everywhere, secure storage is limited. We strongly recommend full vacant possession for the duration. Most clients rent locally — typical 4-bed Victorian terrace rental in zones 2–4 is £4,500–£8,000/month; 24 weeks of rental is £25,000–£45,000. This needs to be in the project budget. The trade-off: a vacant property allows us to work efficient 5-day-week, 8-hour-day shifts with simultaneous trades on multiple floors. Occupied projects extend programme by 30–50% and increase cost by 8–12% due to dust separation, daily clean-down, reduced trade efficiency. We've delivered both ways and will be honest about the trade-off during initial consultation — and help find suitable short-term rental options through our local agent partnerships.
